• 한국지구과학회지
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• 제23권1호
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• pp.1-14
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• 2002

The land-cover of two regions of South and North Korea included in one Landsat TM scene was investigated by comparing different seasons and different band data over the multiple land-cover types. The relationships between the intensities of two bands in the 2-D plot are mainly linear in band2 versus band1 and band3 versus band1, polygonal sporadic in band5 versus band1 and band7 versus band1, and almost tri-polarized in band4 versus band3. The 2-D plot of band4/band3 shows the best capability to discriminate different main land-cover such as water, vegetation and dry soil. Some discriminations are not clear between city and dry field, or mountain and plain field in the scene of September. The digital number data of band4 from vegetated zones show stronger reflectance in September rather than April, while other band values tend to be lager in April than in September over each land-cover. NDVI presents high value in both regions in September. However the image of Wonsan area in April suggests weak vigor of vegetation in comparison with Cholwon area. Band ratios are very effective in eliminating the influence of the complex topography. The proper pairing of the band ratio improved the discrimination capability of the land-cover; band5/band2 for dry soil, band4/band3 for vegetation and band1/band7 for the water. The RGB combination of the three band ratio pairs showed the best results in the discrimination of the land-cover of Wonsan, Cholwon and even the Demilitarized Zone.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1989년도 춘계학술대회
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• pp.45-49
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• 1989

In this paper the feature of background EEG is extracted by LS Prony Method for the analysis of background EEG in the time domain. From the experimential results the alpha band amplitude is the largest among bands and beta band amplitude is larger than that of the delta band and theta band. The sustained time for the alpha band, the beta band, the delta band and the theta band is 2.3461(sec), 1.8980(sec), 0.3120(sec), 0.2930(sec) respectively. Consequently the alpha band and the beta band are maintained in the whole, segment. The delta band, the theta band are existed intermittently in the segment.

• Parasites, Hosts and Diseases
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• 제29권2호
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• pp.113-120
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• 1991

혈청내 특이 항체가를 측정하여 폐흡충증을 면역학적으로 진단할 경우 그 민감도와 특이도가 뛰어난 것은 이미 잘 알려져 있다. 이때에 항원으로 사용하는 폐홉충 추출액의 구성 단백질 중 항원성과 특이성이 높은 단백질을 알면 항원을 질적으로 향상시킬 수 있을 것으로 기대하고 있다. 최근 SDS-PAGE/immuoblot을 이용하여 환자 혈청내의 특이 항체(IgG)와 민감하게 반응하는 폐흡충의 수용성(수준성) 항원 단백질 분획이 보고되고 있다. 그러나 이 단백질 분획은 SDS-PAGE 후 특이항체와 반응한 polypeptide 수준의 subunit이어서 이들이 분해되기 전 성분 단백질 어느 것에서 유래한 것인지를 전혀 알 수 없는 단점이 있다. 따라서, 이와 같은 문제를 해결하고 나아가 종특이(종특리) 항원 단백질을 찾기 위해서는 분해, 변성되기 전의 성분 단백질의 성질을 파악할 필요가 있다. 이 실험에서는 폐흡충 성충 생리식염수 추출액내의 구성 단백질을 파악하고 그 분자량을 측정하기 위하여 Disc-PAGE를 이용한 Ferguson plot과 column chromatography를 실시하였다. 우선 폐홉충 추출액을 4.5~10%까지의 각기 다른 gel 농도에서 전기영동을 실시한 결과 추출액은 최소 8개 이상의 주요 성분 단백질로 구성되어 있었고 각각의 분자량은 band 1은 440kDa, band 2는 386kDa, band 3은 17.4kDa, band 4는 17k3a, band 5는 14.3kDa, band 6은 46kDa, band 7은 38kDa 그리고 band 8은 23k3a 이었다. 이어 추출액을 $1.6({\Phi}){\times}70cm$의 Sephacryl S-300 Supcrfne column을 통과시켜 7분획을 얻은 후 각 분 획을 다시 85 gel에서 전기영동으로 확인한 결과 band 1은 1~3분회, band 2는 2,3분회, band 3은 5분획, band 4는 5,6분획, band 5는 5분획, band 6,7은 3,4분획, band 8은 5분회에서 각각 관찰되어 Ferguson plot에 의해 계산한 분자량과 유사한 결과를 보이고 있었다.

• 대한의용생체공학회:의공학회지
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• 제10권2호
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• pp.131-138
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• 1989

In this paper the feature of background EEG is extracted by LS Prony Method for the analysis of background EEG in the time domain. Autocorrelation leg estimates are not required with the LS Prony method. The Prony method is required any the solution of two serfs of simultaneous linear equation and a polynominal rooting. That the optimal order of this model is the 6-th order is determined by using Akaike' s Information Criterial test. From the experimential results the alpha band amplitude is the largest among alpha band beta band theta band delta band and beta band amplitude is larger than that of the delta band and theta band. The sustained time for the alph a band, the beta band, the delta band and the theta band is 2, 3461 (sec), 0.6490(sec), 0.3120(sec), 0.7046(sec) respectively. Consequenty the alpha band is maintained in the whole subjects, the beta band, the delta band, the theta band are existed intermittently in each subjects.

• Journal of electromagnetic engineering and science
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• 제3권1호
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• pp.23-28
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• 2003

In this paper, a triple-band planar antenna is proposed for the application to miniaturized automobile safety devices operating at X band(10.5 ㎓), K band(24.15 ㎓), and Ka band(34.3 ㎓). The frequency ratio between the resonant frequencies of this antenna can be adjusted from 1.99 to 2.23 for both X band and K band by varying its slit length. Parasitic elements are added on the modified slot loaded antenna to obtain the third resonance. From numerical as well as experimental results, it has been confirmed that this type of antenna is appropriate for planar multi-band antenna systems.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권7호
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• pp.2212-2230
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• 2014

Cognitive radio (CR) users, known as secondary users (SUs), should avoid interference with primary users (PUs) who own the licensed band, while trying to access it; when the licensed band is unused by the PUs. To detect PUs, spectrum sensing should be performed over in-band channels that are currently in use by SUs. If PUs return to access the band, SUs need to vacate it, disrupting the SUs' communication unless a non-utilized band is discovered. Obtaining a non-utilized band in a short period facilitate seamless communication for SUs and avoid interference on PUs by vacating from the channel immediately. Searching for a non-utilized band can be done through proactive out-of-band (OB) sensing. In this paper, we suggest a proactive OB sensing scheme that minimizes the time required to discover a non-utilized spectrum in order to continue communication. Although, the duration spent on OB sensing reduces the throughput of the CR networks that can be achieved on band being utilized, the lost throughput can be compensated in the new discovered band. We demonstrate that, the effect of our proposed scheme on the throughput owing to OB sensing is insignificant, while exhibiting a very short channel discovery time.

• Journal of Communications and Networks
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• 제10권1호
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• pp.71-78
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• 2008

We propose a sub-band spreading technique for adaptive modulation (AM) in orthogonal frequency division multiplexing (OFDM) systems in order to reduce signaling overheads and to average frequency selective fading channels causing different signal-to-noise ratio (SNR) values for subcarriers in each subband. The conventional sub-band based AM schemes can also reduce signaling overheads and complexity for allocating a resource per sub-band at a time. However, they may suffer from the channel variation in a sub-band when the sub-band size is larger than the channel coherence bandwidth (BW). The sub-band spreading at the transmitter enables the received symbols in each sub-band to have an identical reliability even in a frequency selective fading channel. We rigorously analyze the averaged SNR value at the receiver of the sub-band spreading system and the analyzed average SNR in a sub-band is used for an adaptation criterion. The proposed AM scheme outperforms the conventional sub-band based OFDM scheme without spreading, and it can yield better throughput performance than the conventional subcarrier based AM schemes when we consider the signaling overheads.

• Journal of electromagnetic engineering and science
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• 제15권4호
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• pp.232-238
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• 2015

This work describes the development of a D-band (110-170 GHz) signal source based on a SiGe BiCMOS technology. This D-band signal source consists of a V-band (50-75 GHz) oscillator, a V-band amplifier, and a D-band frequency doubler. The V-band signal from the oscillator is amplified for power boost, and then the frequency is doubled for D-band signal generation. The V-band oscillator showed an output power of 2.7 dBm at 67.3 GHz. Including a buffer stage, it had a DC power consumption of 145 mW. The peak gain of the V-band amplifier was 10.9 dB, which was achieved at 64.0 GHz and consumed 110 mW of DC power. The active frequency doubler consumed 60 mW for D-band signal generation. The integrated D-band source exhibited a measured output oscillation frequency of 133.2 GHz with an output power of 3.1 dBm and a phase noise of -107.2 dBc/Hz at 10 MHz offset. The chip size is $900{\times}1,890{\mu}m^2$, including RF and DC pads.

• Journal of electromagnetic engineering and science
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• 제16권1호
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• pp.35-43
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• 2016

A compact ultra-wide band antenna with a quadruple band-notched characteristic is proposed. The proposed antenna consists of a slotted trapezoid patch radiator, an inverted U-shaped band stop filter, a pair of C-shaped band stop filters, and a rectangular ground plane. To realize the quadruple notch-band characteristic, a U-shaped slot, a complementary split ring resonator, an inverted U-shaped band stop filter, and two C-shaped band stop filters are utilized in this antenna. The antenna satisfies the -10 dB reflection coefficient bandwidth requirement in the frequency band of 2.88-12.67 GHz, with a band-rejection characteristic in the WiMAX (3.43-3.85 GHz), WLAN (5.26-6.01 GHz), X-band satellite communication (7.05-7.68 GHz), and ITU 8 GHz (8.08-8.87 GHz) signal bands. In addition, the proposed antenna has a compact volume of $30mm{\times}33.5mm{\times}0.8mm$ while maintaining omnidirectional patterns in the H-plane. The experimental and simulated results of the proposed antenna are shown to be in good agreement.

• 대한음성학회:학술대회논문집
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• 대한음성학회 2007년도 한국음성과학회 공동학술대회 발표논문집
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• pp.127-130
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• 2007

The conventional feature recombination technique is very effective in the band-limited noise condition, but in broad-band noise condition, the conventional feature recombination technique does not produce notable performance improvement compared with the full-band system. To cope with this drawback, we introduce a new technique of sub-band likelihood computation in the feature recombination, and propose a new feature recombination method by using this sub-band likelihood computation. Furthermore, the reliable sub-band selection based on the signal-to-noise ratio is used to improve the performance of this proposed feature recombination. Experimental results shows that the average error reduction rate in various noise condition is more than 27% compared with the conventional full-band speaker identification system.